@article {1337, title = {Assessment of the Antifungal Effect of Camellia sinensis Extracts on Candida albicans and Candida parapsilosis Strains-An in vitro Study}, journal = {Pharmacognosy Research}, volume = {17}, year = {2025}, month = {January 2025}, pages = {70-77}, type = {Original Article}, chapter = {70}, abstract = {

Background: Oral candidiasis is a common infection caused by Candida species, Candida albicans and Candida parapsilosis being the most prevalent strains. Objectives:\ To assess the antifungal effects of Camellia sinensis (green tea) extracts on standardized Candida albicans and Candida parapsilosis strains, depending on the extraction solvent and extract concentration. Materials and Methods:Extracts with concentrations of 25 and 50\% were prepared, using methanol and ethanol as solvents. A 0.5 McFarland concentration and approximate 2x10$^{6}$ CFU/mL suspension of each Candida strain was prepared. The four types of extracts were applied on unimpregnated paper discs placed on four Petri dishes with Sabouraud Glucose with Chloramphenicol Agar culture medium. A Dimethyl sulfoxide solution was used as negative control, and a fluconazole impregnated disc was used as positive control. After a 24 hr incubation period, the inhibition zones were measured. The minimum inhibitory concentration was determined. Results: The largest inhibition zone was measured for the positive control, while the negative control showed no inhibitory effect. The 50\% concentration extracts showed larger inhibition zones compared to 25\% concentration, for both ethanol and methanol solvents and for both Candida albicans and Candida parapsilosis strains, but lower compared to the positive control. No significant differences were determined when comparing the antifungal effects of same concentration extracts prepared with methanol and ethanol as solvents. Conclusion: The green tea extract shows the ability to inhibit the growth of standardized Candida albicans and Candida parapsilosis stains. Its efficacy increases with concentration, and is not dependent on the solvent type.

}, keywords = {Antifungal, Camellia Sinensis, Candida albicans, Candida parapsilosis, Green tea, Oral Candidiasis}, doi = {10.5530/pres.20251913}, author = {Florin Iacob and Lavinia Cosmina Ardelean and Alexandra Roi and Ioana Tomoiaga and Delia Muntean and Laura-Cristina Rusu} } @article {531, title = {Quantification of Total Polyphenols, Catechin, Caffeine, L-theanine, Determination of Antioxidant Activity and Effect on Antileishmanial Drugs of Ethiopian Tea Leaves Extracts}, journal = {Pharmacognosy Research}, volume = {7}, year = {2015}, month = {June 2015}, pages = {s7-s14}, type = {Original Article }, chapter = {s7}, abstract = {

Objective:\ In this study four tea samples Gumero black, Wushwush black and Wushwush green from Agri- Ceft Plc and East Africa black tea leaves from East African Agribusiness Plc were investigated for total polyphenols, caffeine, catechin and L-theanine content.\ Materials and Methods:\ The aqueous extracts were investigated for their antioxidant and antileishmanial property and effect on amphotericin B, miltefocine and sodium stibogluconate, the commonly used antileishmanial drugs. Antileishmanial studies were conducted on\ L. aethiopica.\ Results:\ Wushwush green tea had the highest content of polyphenol (19.98 {\textpm} 1.15 mg gallic acid equivalent /100 g dry leaf weight), catechin (37.06 mg/g) and L-theanine (48.54 mg/g but the lowest caffeine content). It exhibited the highest antioxidant activity. The highest antioxidant effect of Wushwush green tea may be attributed to the highest polyphenol content. East African black tea had the lowest L-theanine (20.72 mg/g) and antioxidant activity but the highest caffeine (16.60 mg/g) content.\ Conclusion:\ Wushwush green tea showed slight inhibitory effect on\ L. aethiopica\ while the lack tea extracts (Gumero, East Africa and Wushwush) exhibited no antileishmanial activity. Wushwush green tea did not show any synergistic or antagonistic effect on the antileishmanial drugs used in this study while Gumero, East Africa and Wushwush black tea extracts exhibited dose dependant inhibitory activity to the commonly used antileishmanial drugs included in this study.

}, keywords = {Caffeine, Camellia Sinensis, Catechin, L-theanine, Polyphenols}, doi = {10.4103/0974-8490.157991 }, author = {Alemu Tadesse and Ariaya Hymete and Adnan A Bekhit and Salahuddin Farooq Mohammed} } @article {858, title = {A Modified MS2 Bacteriophage Plaque Reduction Assay for the Rapid Screening of Antiviral Plant Extracts}, journal = {Pharmacognosy Research}, volume = {2}, year = {2010}, month = {September 2010}, pages = {221-228}, type = {Original Article}, chapter = {221}, abstract = {

Introduction: Traditional methods of screening plant extracts and purified components for antiviral activity require up to a week to perform, prompting the need to develop more rapid quantitative methods to measure the ability of plant based preparations to block viral replication. We describe an adaption of an MS2 plaque reduction assay for use in S. aureus. Results: MS2 bacteriophage was capable of infecting and replicating in B. cereus, S. aureus and F+ E. coli but not F- E. coli. Indeed, both B. cereus and S. aureus were more sensitive to MS2 induced lysis than F+ E. coli. When MS2 bacteriophage was mixed with Camellia sinensis extract (1 mg/ml), Scaevola spinescens extract (1 mg/ml) or Aloe barbadensis juice and the mixtures inoculated into S. aureus, the formation of plaques was reduced to 8.9 {\textpm} 3.8\%, 5.4 {\textpm} 2.4\% and 72.7 {\textpm} 20.9\% of the untreated MS2 control values respectively. Conclusions: The ability of the MS2 plaque reduction assay to detect antiviral activity in these known antiviral plant preparations indicates its suitability as an antiviral screening tool. An advantage of this assay compared with traditionally used cytopathic effect reduction assays and replicon based assays is the more rapid acquisition of results. Antiviral activity was detected within 24 h of the start of testing. The MS2 assay is also inexpensive and non-pathogenic to humans making it ideal for initial screening studies or as a simulant for pathogenic viruses.

}, keywords = {Aloe vera, Antiviral assay, Camellia Sinensis, MS2 bacteriophage, Plaque reduction assay, Scaevola spinescens}, doi = {10.4103/0974-8490.69108}, author = {Ian Cock and FR Kalt} } @article {588, title = {Diuretic activity of Sri Lankan black tea (Camellia sinensis L.) in rats}, journal = {Pharmacognosy Research}, volume = {1}, year = {2009}, month = {January 2010 }, pages = {4-10}, type = {Original Article}, chapter = {4}, abstract = {

The aim of this study was to evaluate the diuretic potential of Sri Lankan black tea (Camellia sinensis L.). This was assessed in rats using high grown Dust grade No: 1 tea, which is consumed widely by the tea drinkers worldwide. Different doses of hot black tea brew (BTB) (84, 167, 501 or 1336 mg/ml respectively equivalent to 1.5, 3, 9 and 24 cups) were made and orally administered to previously starved (24 h) but subsequently hydrated (with 15 ml of isotonic saline) rats and their urinary output was monitored cumulatively at hourly intervals for 6h. The reference drug used was frusemide (13 mg/kg). The results showed that BTB induced significant (P \< 0.05), mild to moderate and dose- dependent diuresis (starting from 167 mg/ml). This diuretic activity had a fairly rapid onset (within 2 h) and relatively short duration of action (3 h). BTB also significantly (P \< 0.05) increased the overall urinary frequency. Further, the diuretic activity of BTB was less potent to frusemide (by 45\%). Decaffeination of black tea almost completely abolished the diuresis. The diuresis of the BTB was solely due to increased (by 55 \%) urinary Na+ excretion (with no urinary K+ loss). Further, the chronic daily administration of the BTB did not develop tolerance or induce toxicity (general, renal and hepatic). It is concluded that BTB made from Sri Lankan high grown Dust grade No :1 tea has safe, mild to moderate diuretic activity with rapid onset and relatively short duration of action. Further, this study supports the claim made by Sri Lankan indigenous physicians that it is a diuretic.

}, keywords = {Black tea, Camellia Sinensis, Diuresis, Dust grade tea, Sri Lankan tea}, author = {W.D. Ratnasooriya and T.S.P. Fernando and R.A.A.R Ranatunga} }